Fastening device



FIG. 1 is a front, top, right side perspective view of a fastening device;

FIG. 2 is a rear, bottom, left side perspective view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a rear view thereof; and,

FIG. 7 is a right side view thereof, the left side view being a mirror image.

The broken lines in the figures depict portions of a fastening device that form no part of the claimed design. 

CLAIM The ornamental design for a fastening device, as shown and described. 